W3School TIY
编辑您的代码：
<html> <head> <script type="text/javascript"> function checkLen(x,y) { if (y.length==x.maxLength) { var next=x.tabIndex if (next<document.getElementById("myForm").length) { document.getElementById("myForm").elements[next].focus() } } } </script> </head> <body> <p>这段脚本在达到文本框的最大长度时跳到下一个文本框：</p> <form id="myForm"> <input size="3" tabindex="1" maxlength="3" onkeyup="checkLen(this,this.value)"> <input size="2" tabindex="2" maxlength="2" onkeyup="checkLen(this,this.value)"> <input size="3" tabindex="3" maxlength="3" onkeyup="checkLen(this,this.value)"> </form> </body> </html>
查看结果: